Reduced miR-105-1 levels are associated with poor survival of patients with non-small cell lung cancer.

Altered expression of microRNAs (miRNAs or miRs) contributes to lung carcinogenesis. The present study performed an analysis of differentially expressed miRNAs in different peripheral blood samples from patients with various diseases vs. controls using the Gene Expression Omnibus (GEO) database data, and assessed miR-105-1 expression in 32 normal lung and 142 non-small cell lung cancer (NSCLC) tissue samples using reverse transcription-quantitative polymerase chain reaction. Survival data were calculated using Kaplan-Meier curves and a log-rank test. The stepwise forward Cox regression model was performed for univariate and multivariate analyses of independent predictor of overall survival (OS) of patients. The data on and tissue microarray analyses of miRNA expression revealed reduced miR-105-1 expression in different types of human cancer, particularly in NSCLC. The level of miR-105-1 expression was confirmed to be downregulated in NSCLC tissues compared with that in normal lung tissues. Reduced miR-105-1 expression was associated with larger tumor size as well as poor OS and disease-free survival (DFS) of patients. Multivariate survival analysis demonstrated that reduced miR-105-1 expression and tumor size were independent predictors for OS of NSCLC patients. In conclusion, reduced miR-105-1 expression in NSCLC tissues is associated with poor OS and DFS of NSCLC patients.